You genuinely appreciate all the hard work that your co-op's board of directors does. The board members clearly take their responsibilities to heart. They're also a pretty diverse lot, so there's a lot of give-and-take on the important issues -- except for that one guy.
One board member always seems to have a specific agenda and doesn't really care about anybody else's perspective. The disagreements no longer seem healthy or reasonable. The board is bogged down with picky disputes that all originate from a single source and that person's behavior has grown increasingly disruptive and offensive.
Is it time to remove that member of the board? Can it even be done?
Maybe. If the board member's actions are just misguided, it may be better to try corrective action before you move to terminate them from their position. It can be difficult to remove a board member just because they offer unpopular opinions or advocate strongly for their position.
On the other hand, you have every reason to try to remove a board member who has a conflict of interest they haven't disclosed or otherwise breaches their duty. If the troublesome board member shows up intoxicated or high to meetings, that's another good reason to act. Unethical behavior -- like pressuring co-op members with threats or dipping into co-op funds for their personal expenses -- is another significant issue.
Typically, the first step toward removing a board member involves checking the co-op's bylaws to see what provisions exist for this situation. Most likely, you'll have to call for a special meeting and ask the shareholders to vote on the board member's removal.
If your cooperative is in trouble because of a problematic board member, you need to take action. It may be wisest, however, to have a consultation with an experienced attorney as soon as possible.